History and Authors
Authors
The software was mainly written by Dr. Christian Lage. First versions and ideas of the software appear already in his PhD. thesis. The current version 1.4 was developed during his post doctoral studies at the Seminar for Applied Mathematics of the Swiss Federal Institute of Technology (ETH), Zurich. The design ideas leading to this version are summarized in the technical report 1998-07
Ana-Maria Matache was working with the hp-FEM part of Concepts. She implemented the quadrilaterals for 2D problems together with Christian during her Ph.D. thesis (finished in 2000). She is the one I have asked if I did not know what happened in the code. She also gave me the first introductions to Concepts.
Gregor Schmidlin is working with the BEM part of Concepts.
In summer 1999, two students (David Hoch and Andreas Rüegg) wrote a Semesterarbeit on and with Concepts-1.4. They implemented mixed and variable boundary conditions for hp-FEM. Their work was supervised by Ana-Maria. After their Semesterarbeit, David and Andreas continued to work on Concepts: a direct sparse solver (SuperLU) and linear elasticity.
During the winter 1999/2000 term, Philipp Frauenfelder wrote his diploma thesis on and with Concepts. He implemented hp-DGFEM for second order PDE with constant coefficients and mixed and variable boundary conditions.
During the winter 2000/2001 term, Giacomo Catenazzi implemented linear elasticity in a somewhat more general way. At the same time, Andreas Rüegg wrote his diploma thesis about generalized FEM. David Hoch implemented non reflecting boundary conditions and time stepping schemes in Concepts for his diploma thesis.
Since spring 2000, Philipp Frauenfelder is working on 3D hp FEM.
In spring 2002, Kersten Schmidt started working on vector valued problems (with Maxwell equations in mind).
In the Sommersemester 2002, Manuel Walser designed and implemented time stepping schemes (in particular Newmark) for discretized problems. Norbert Fernandes designed and implemented an interface to the Eigenvalue solver JdbSym.
In the Wintersemester 2002/2003, Christoph Winkelmann and Adrian Burri used Concepts to solve non-linear convection-diffusion problems using a Finite Volume Discontinuous Galerkin Scheme. During their work, the timestepping classes where improved considerably.
Since early 2003, Radu Todor is using Concepts to solve stochastic PDEs.
Versions
Up to summer 2001, version 1.4 was used for computations and for development. Starting in summer 2001, Christian Lage and Philipp Frauenfelder started to write a new build environment which could be used for the further development.
While switching to the new build environment, we also decided to use some more modern C++ features such as namespaces and exceptions. In addition, we (Gregor Schmidlin and Philipp Frauenfelder) intend to add parallelization. In our opinion, this justifies going to version 2.0.
Documentation
Unfortunately, very little of the code was commented right in the source by Christian. Until recently, one had to read Christian's papers which dealt with Concepts to understand the working of the software. Or you had to ask him or Ana-Maria Matache directly.
During his diploma thesis, Philipp started to write some documentation of the code into the source. In order to make his comments available to a larger public, he used DOC++. For version 2.0, we switched to Doxygen.